Even though my symathies towards Bayern Munich are definitely higher than the one for Borussia dortmund i am also not really happy with that transfer. First of all i think it will definitely weaken Dortmund quite a bit because Guerrero definitely was one of their best players. At the same time though i think that he will have a very hard time to get into the starting Eleven of Bayern. I just don't think that he is stronger than any of the current Bayern players. He is very versatile though.
Guerrero was getting last season again a good player as he has got long time down , but yeah he is for sure a loss for Dortmund and good thing for Bayern Munich.
I guess he will be for sure working hard to get into the starting Team and he has the quality for that.
But yes its always hard at Bayern Munich to get into team , best example was Mane last season.